GtkosxApplication

GtkosxApplication — Base class for OS X integration

Functions

Signals

Types and Values

Object Hierarchy

    GObject
    ╰── GtkosxApplication

Includes

#include <gtkosxapplication.h>

Description

Exposes to the Gtk+ program important functions of OS X's NSApplication class for use by Gtk+ applications running with the quartz Gdk backend and provides addtional functions for integrating a Gtk+ program into the OS X user environment.

Using GtkosxApplication is pretty simple. First, create an instance at startup:

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GtkosxApplication *theApp = g_object_new(GTKOSX_TYPE_APPLICATION, NULL);

Do this early in your program, shortly after you run

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gtk_init()

Don't forget to guard it, and all other calls into the library, with

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#ifdef MAC_INTEGRATION

You don't want your Linux users' builds failing because of this. The application object is a singleton, so you can call g_object_new as often as you like. You'll always get the same pointer back. There's no need to pass it around as an argument. Do note that all of the GtkosxApplication functions take theApp as an argument, even if they don't use it. This seems silly in C, and perhaps it is, but it's needed to make the Python binding logic recognize that they're class methods.

Just having the application object created will get you some benefits, like having the Quit menu item in the dock menu work. But you'll obviously want more. So the next place to visit is your main window code. If you have a simple application, you might be constructing the menu by hand, but you're more likely to be using GtkBuilder. In either case, you need to get a pointer to the menubar. If you're building by hand, you've already got it lying around because you needed it to add the menus to. With GtkBuilder, you need to ask the GtkUIManager for a pointer. Once everything is more-or-less set up on the Gtk+ side, you need only hide the menu and call gtkosx_application_set_main_menu(). Here's an example with GtkBuilder:

Setting the MenuBar

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GtkUIManager *mgr = gtk_ui_manager_new();
GtkosxApplication *theApp = g_object_new(GTKOSX_TYPE_APPLICATION, NULL);
...
mergeid = gtk_ui_manager_add_ui_from_file(mgr, "src/testui.xml", &err);
...
menubar = gtk_ui_manager_get_widget(mgr, "/menubar");
gtk_widget_hide (menubar);
gtkosx_application_set_menu_bar(theApp, GTK_MENU_SHELL(menubar));

There are a couple of wrinkles, though, if you use accelerators. First off, there are two event paths for accelerators: Quartz, where the keystroke is processed by OS X and the menu item action event is placed on the event queue by OS X, or Gtk, where the accelerator key event is passed through to Gtk to recognize. This is controlled by gtkosx_application_set_use_quartz_accelerators() (you can test the value with gtkosx_application_use_quartz_accelerators()), and the default is to use Quartz handling. This has two advantages:

  • It works without any extra steps

  • It changes stock accelerators (like Ctrl-O for open file) to the stock OS X keyEquivalent (Cmd-O in that case).

If you need to use Gtk+ keyboard accelerator handling *and* you're using GtkMenuItems instead of GtkActions, you'll need to connect a special handler as shown in the following example:

Enabling Accelerators on Hidden Menus

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static gboolean
can_activate_cb(GtkWidget* widget, guint signal_id, gpointer data)
{
  return gtk_widget_is_sensitive(widget);
}
...
  g_signal_connect(menubar, "can-activate-accel",
                   G_CALLBACK(can_activate_cb), NULL);

The next task to make your application appear more normal for Mac users is to move some menu items from their normal Gtk locations to the so-called "App" menu. That's the menu all the way at the left of the menubar that has the currently-running application's name. There are 3 menu items that normally go there:

  • Help|About

  • Edit|Preferences

  • File|Quit

File|Quit is a special case, because OS X handles it itself and automatically includes it, so the only thing you need do is hide it on the File menu so that it doesn't show up twice:

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gtk_widget_hide(GTK_WIDGET(file_quit_menu_item));

The other two must be moved in code, and there are two functions for doing that. The first one creates "goups", which is just an easy way to manage separators, and the second adds the actual menu items to the groups. Here's an example:

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GtkosxApplicationMenuGroup *group;
GtkMenuItem *about_item, *preferences_item;
about_item = gtk_ui_manager_get_widget(mgr, "/menubar/Help/About");
preferences_item = gtk_ui_manager_get_widget(mgr, "/menubar/Edit/Preferences");

group = gtkosx_application_add_app_menu_group (theApp);
gtkosx_application_add_app_menu_item  (theApp, group,
                                       GTK_MENU_ITEM (about_item));

group = gtkosx_application_add_app_menu_group (theApp);
gtkosx_application_add_app_menu_item  (theApp, group,
                                       GTK_MENU_ITEM (preferences_item));

Once we have everything set up for as many windows as we're going to open before we call gtk_main_loop(), we need to tell OS X that we're ready:

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gtkosx_application_ready(theApp);

If you add other windows later, you must do everything above for each one's menubar. Most of the time the internal notifictations will ensure that the GtkosxApplication is able to keep everything in sync. However, if you at any time disconnect or block signals and change the menu (perhaps because of a context change within a window, as with changing pages in a GtkNotebook) you need to call

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gtkosx_application_sync_menubar(theApp)

N.B.: One GtkMenu function, gtk_menu_reorder_child(), changes the menu appearance without emitting a signal, so if you use that function in your code you'll need to call gtkosx_application_sync_menubar() afterwards.

Dock Support

The dock is that bar of icons that normally lives at the bottom of the display on a Mac (though it can be moved to one of the other sides; this author likes his on the left, which is where it was originally on a NeXT). Each running application has a "dock tile", an icon on the dock. Users can, if they like, add application (or document) icons to the dock, and those can be used to launch the application. Apple allows limited customization of the dock tile, and GtkosxApplication has an interface for adding to the dock's menu and for changing the icon that is displayed for the the application. GtkosxApplication also provides an interface to AttentionRequest, which bounces the dock tile if the application doesn't have focus. You might want to do that at the end of a long task so that the user will know that it's finished if she's switched to another application while she waits for yours. They're all pretty simple, so you can just read the details below.

  • gtkosx_application_set_doc_menu()

  • gtkosx_application_set_doc_icon_pixbuf()

  • gtkosx_application_set_dock_icon_resource()

  • gtkosx_application_attention_request()

  • gtkosx_application_cancel_attention_request()

Bundle Support

The last feature to which GtkosxApplication provides an interface is the bundle. Normally in OS X, graphical applications are packaged along with their non-standard dependencies and their resources (graphical elements, translations, and such) in special directory structures called "bundles". To easily package your Gtk+ application, have a look at gtk-mac-bundler, also available from the Gtk-OSX project.

OS X provides a variety of functions pertaining to bundles, most of which are not likely to interest someone porting a Gtk+ application. GtkosxApplication has wrapped a few that might be:

  • gtkosx_application_get_bundle_path()

  • gtkosx_application_get_resource_path()

  • gtkosx_application_get_executable_path()

  • gtkosx_application_get_bundle_id()

  • gtkosx_application_get_bundle_info()

The first three just get a UTF8-encoded path. An interesting note is that they'll return the path to the executable or the folder it's in regardless of whether it's actually in a bundle. To find out if one is actually dealing with a bundle, gtkosx_application_get_bundle_id() will return "" if it can't find the key CFBundleIdentifier from the bundle's Info.plist -- which it won't if the application isn't in a bundle or wasn't launched by opening the bundle. (In other words, even if you have your application installed in Foo.app, if you launch it from the command line as

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$ Foo.app/Contents/MacOS/Foo

the Info.plist won't have been opened and gtkosx_application_get_bundle_id() will return "". Of course, it will also return "" if you didn't set CFBundleIdentifier in the Info.plist, so make sure that you do!

The last function, gtkosx_application_get_bundle_info(), will return the value associated with an arbitrary key from Info.plist as long as that value is a string. If it isn't, then the function returns a null string ("").

Notifications

Finally, notice the signals. These are emitted in response to the indicated OS X notifications. Except for “NSApplicationBlockTermination”, most programs won't need to do anything with them. “NSApplicationBlockTermination” is telling you that OS X is planning to shut down your program. If you have any cleanup to do (like saving open files), or if you want to ask the user if it's OK, you should connect to the signal and do your cleanup. Your handler can return TRUE to prevent the application from quitting.

Functions

gtkosx_application_get ()

GtkosxApplication *
gtkosx_application_get (void);

Get the singleton NSApplication object.

Returns

the singleton application object.

[transfer none]


gtkosx_application_ready ()

void
gtkosx_application_ready (GtkosxApplication *self);

Inform Cocoa that application initialization is complete.

Parameters

self

The GtkosxApplication object

 

gtkosx_application_set_use_quartz_accelerators ()

void
gtkosx_application_set_use_quartz_accelerators
                               (GtkosxApplication *self,
                                gboolean use_quartz_accelerators);

Set quartz accelerator handling; TRUE (default) uses quartz; FALSE uses Gtk+. Quartz accelerator handling is required for normal OS X accelerators (e.g., command-q to quit) to work.

Parameters

self

The GtkosxApplication pointer.

 

use_quartz_accelerators

Gboolean

 

gtkosx_application_use_quartz_accelerators ()

gboolean
gtkosx_application_use_quartz_accelerators
                               (GtkosxApplication *self);

Are we using Quartz or Gtk+ accelerator handling?

Parameters

self

The GtkosxApplication pointer.

 

Returns

a gboolean


gtkosx_application_set_menu_bar ()

void
gtkosx_application_set_menu_bar (GtkosxApplication *self,
                                 GtkMenuShell *menu_shell);

Set a window's menubar as the application menu bar. Call this once for each window as you create them. It works best if the menubar is reasonably fully populated before you call it. Once set, it will stay syncronized through signals as long as you don't disconnect or block them.

Parameters

self

The GtkosxApplication object

 

menu_shell

The GtkMenuBar that you want to set.

 

gtkosx_application_sync_menubar ()

void
gtkosx_application_sync_menubar (GtkosxApplication *self);

Syncronize the active window's GtkMenuBar with the OSX menu bar. You should only need this if you have programmatically changed the menus with signals blocked or disconnected.

Parameters

self

The GtkosxApplication object

 

gtkosx_application_insert_app_menu_item ()

void
gtkosx_application_insert_app_menu_item
                               (GtkosxApplication *self,
                                GtkWidget *menu_item,
                                gint index);

Certain menu items (About, Check for updates, and Preferences in particular) are normally found in the so-called Application menu (the first one on the menubar, named after the application) in OSX applications. This function will create a menu entry for such a menu item, removing it from its original menu in the Gtk application.

Any items inserted at index zero will have the app name appended; this is intended for the "About" menu item, so that it says "About Foo" like most Mac programs, without having to worry too much about how "About" is spelled/translated.

To group your menu items, insert GtkSeparatorMenuItem*s where you want them.

Don't use it for Quit! A Quit menu item is created automatically along with the Application menu. Just hide your Gtk Quit menu item.

Parameters

self

The GtkosxApplication object

 

menu_item

The GtkMenuItem to add to the group.

 

index

The place in the app menu that you want the item inserted. The first item is 0.

 

gtkosx_application_set_about_item ()

void
gtkosx_application_set_about_item (GtkosxApplication *self,
                                   GtkWidget *item);

Sets the designated menu item as the "About <appname>", the first one on the App Menu. We take a GtkMenuItem* because it's less work for app developers than unwrapping a GtkAction for us to wrap in an NSAction.

Parameters

self

The application object

 

item

The about menu item

 

gtkosx_application_set_window_menu ()

void
gtkosx_application_set_window_menu (GtkosxApplication *self,
                                    GtkMenuItem *menu_item);

Sets a designated menu item already on the menu bar as the Window menu. This is the menu which contains a list of open windows for the application; by default it also provides menu items to minimize and zoom the current window and to bring all windows to the front. Call this after gtk_osx_application_set_menu_bar(). It operates on the currently active menubar. If nenu_item is NULL, it will create a new menu for you, which will not be gettext translatable.

Parameters

self

The application object

 

menu_item

The menu item which will be set as the Window menu

 

gtkosx_application_set_help_menu ()

void
gtkosx_application_set_help_menu (GtkosxApplication *self,
                                  GtkMenuItem *menu_item);

Sets a designated menu item already on the menu bar as the Help menu. Call this after gtk_osx_application_set_menu_bar(), but before gtk_osx_application_window_menu(), especially if you're letting GtkosxApplication create a Window menu for you (it helps position the Window menu correctly). It operates on the currently active menubar. If nenu_item is NULL, it will create a new menu for you, which will not be gettext translatable.

Parameters

self

The application object

 

menu_item

The menu item which will be set as the Window menu

 

gtkosx_application_set_dock_menu ()

void
gtkosx_application_set_dock_menu (GtkosxApplication *self,
                                  GtkMenuShell *menu_shell);

Set a GtkMenu as the dock menu.

This menu does not have a "sync" function, so changes made while signals are disconnected will not update the menu which appears in the dock, and may produce strange results or crashes if a GtkMenuItem or GtkAction associated with a dock menu item is deallocated.

Parameters

self

The GtkosxApplication object

 

menu_shell

A GtkMenu (cast it with GTK_MENU_SHELL() when you pass it in

 

gtkosx_application_set_dock_icon_pixbuf ()

void
gtkosx_application_set_dock_icon_pixbuf
                               (GtkosxApplication *self,
                                GdkPixbuf *pixbuf);

Set the dock icon from a GdkPixbuf

Parameters

self

The GtkosxApplication

 

pixbuf

The pixbuf. Pass NULL to reset the icon to its default.

 

gtkosx_application_set_dock_icon_resource ()

void
gtkosx_application_set_dock_icon_resource
                               (GtkosxApplication *self,
                                const gchar *name,
                                const gchar *type,
                                const gchar *subdir);

Set the dock icon from an image file in the bundle/

Parameters

self

The GtkosxApplication

 

name

The ame of the image file

 

type

The extension (e.g., jpg) of the filename

 

subdir

The subdirectory of $Bundle/Contents/Resources in which to look for the file.

 

gtkosx_application_attention_request ()

gint
gtkosx_application_attention_request (GtkosxApplication *self,
                                      GtkosxApplicationAttentionType type);

Create an attention request. If type is CRITICAL_REQUEST, the dock icon will bounce until cancelled the application receives focus; otherwise it will bounce for 1 second -- but the attention request will remain asserted until cancelled or the application receives focus. This function has no effect if the application has focus.

Parameters

self

The GtkosxApplication pointer

 

type

CRITICAL_REQUEST or INFO_REQUEST

 

Returns

A the attention request ID. Pass this id to gtkosx_application_cancel_attention_request.


gtkosx_application_cancel_attention_request ()

void
gtkosx_application_cancel_attention_request
                               (GtkosxApplication *self,
                                gint id);

Cancel an attention request created with gtkosx_application_attention_request.

Parameters

self

The application

 

id

The integer attention request id returned from gtkosx_application_attention_request.

 

gtkosx_application_get_bundle_path ()

gchar *
gtkosx_application_get_bundle_path (void);

Return the root path of the bundle or the directory containing the executable if it isn't actually a bundle.

Returns

path The bundle's absolute path or NULL on error. g_free() it when done.


gtkosx_application_get_resource_path ()

gchar *
gtkosx_application_get_resource_path (void);

Return the Resource path for the bundle or the directory containing the executable if it isn't actually a bundle. Use gtkosx_application_get_bundle_id() to check (it will return NULL if it's not a bundle).

Returns

path The absolute resource path. or NULL on error. g_free() it when done.


gtkosx_application_get_executable_path ()

gchar *
gtkosx_application_get_executable_path
                               (void);

Return the executable path, including file name

Returns

The path to the primary executable, or NULL if it can't find one. g_free() it when done


gtkosx_application_get_bundle_id ()

gchar *
gtkosx_application_get_bundle_id (void);

Return the value of the CFBundleIdentifier key from the bundle's Info.plist

This will return NULL if it's not really a bundle, there's no Info.plist, or if Info.plist doesn't have a CFBundleIdentifier key (So if you need to detect being in a bundle, make sure that your bundle has that key!)

Returns

The string value of CFBundleIdentifier, or NULL if there is none. g_free() it when done.


gtkosx_application_get_bundle_info ()

gchar *
gtkosx_application_get_bundle_info (const gchar *key);

Queries the bundle's Info.plist with key. If the returned object is a string, returns that; otherwise returns NULL.

Parameters

key

The key, as a normal UTF8 string.

 

Returns

A UTF8-encoded string. g_free() it when done.

Types and Values

struct GtkosxApplicationMenuGroup

struct GtkosxApplicationMenuGroup {
  GList *items;
};

A menu group is used to collect menu items between separators in the Application menu.

Members

GList *items;

List of menu items in the group.

 

enum GtkosxApplicationAttentionType

The possible values for dock attention requests.

Members

CRITICAL_REQUEST

Bounce the icon until the app is activated.

 

INFO_REQUEST

Bounce the icon for one second.

 

Signal Details

The “NSApplicationBlockTermination” signal

gboolean
user_function (GtkosxApplication *app,
               gpointer           user_data)

Emitted by the Application Delegate when the application reeeives an NSApplicationShouldTerminate notification. Perform any cleanup you need to do (e.g., saving files) before exiting. Returning FALSE will allow further handlers to run and if none return TRUE, the application to shut down. Returning TRUE will veto shutdown and stop emission, so later handlers will not run.

Parameters

app

The application object

 

user_data

Data appended at connection

 

user_data

user data set when the signal handler was connected.

 

Returns

Boolean indicating that further emission and application termination should be blocked.

Flags: Action


The “NSApplicationDidBecomeActive” signal

void
user_function (GtkosxApplication *app,
               gpointer           user_data)

Emitted by the Application Delegate when the application receives an NSApplicationDidBecomeActive notification. Connect a handler if there is anything you need to do when the application is activated.

Parameters

app

The application object user_data: Data appended at connection

 

user_data

user data set when the signal handler was connected.

 

Flags: Action


The “NSApplicationOpenFile” signal

gboolean
user_function (GtkosxApplication *app,
               char              *path,
               gpointer           user_data)

Emitted when a OpenFile, OpenFiles, or OpenEmptyFile event is received from the operating system. This signal does not implement drops, but it does implement "open with" events from Finder. An OpenEmptyFile is received at launch in Python applications.

Parameters

app

The application object

 

path

A UTF8-encoded file path to open.

 

user_data

Data attached at connection

 

user_data

user data set when the signal handler was connected.

 

Returns

Boolean indicating success at opening the file.

Flags: Action


The “NSApplicationWillResignActive” signal

void
user_function (GtkosxApplication *app,
               gpointer           user_data)

This signal is emitted by the Application Delegate when the application receives an NSApplicationWillResignActive notification. Connect a handler to it if there's anything your application needs to do to prepare for inactivity.

Parameters

app

The application object

 

user_data

Data appended at connection

 

user_data

user data set when the signal handler was connected.

 

Flags: Action


The “NSApplicationWillTerminate” signal

void
user_function (GtkosxApplication *app,
               gpointer           user_data)

Emitted by the Application Delegate when the application reeeives an NSApplicationSWillTerminate notification. Connect your final shutdown routine (the one that calls gtk_main_quit() here.

Parameters

app

The application object

 

user_data

Data appended at connection

 

user_data

user data set when the signal handler was connected.

 

Flags: Action